1. Field of the Invention
The present invention relates to a recording-medium recording/reproducing device, and, in particular, to a recording-medium recording/reproducing device having a head moving mechanism which causes a head to approach a recording medium in response to movement of the recording medium, which movement is performed by a recording-medium moving mechanism.
2. Description of the Related Art
In an electronic apparatus such as a personal computer, a word processor or the like, a magnetic disk device, for example, is provided as means for recording information. In the magnetic disk device, when a disk cartridge as a recording-medium container is loaded, a magnetic disk contained in the disk cartridge is rotated, and a magnetic head slides on the magnetic disk so as to perform magnetic recording/reproducing.
The magnetic disk device has a recording-medium moving mechanism which includes a disk holder in which the disk cartridge is inserted, and a slider which performs a sliding operation in response to a disk-cartridge inserting operation and moves the disk holder from a cartridge insertion/ejection position to a cartridge loaded position.
Force is applied to the slider in one direction by a coil spring or the like. When the disk cartridge is inserted, a latch lever is pushed by an end of the disk cartridge so as to rotate, and, thereby, prevention of movement of the slider by the latch lever is released. As a result, the slider slides in the direction in which the force is applied thereto, and moves the disk holder to the cartridge loaded position. At this time, as a result of the disk holder falling from the cartridge insertion/ejection position to the cartridge loaded position, the disk in the disk cartridge is chucked onto a turntable.
In order to positively perform this loading operation performed by the disk holder, the force of the spring to be applied to the slider is set to be strong. The slider is accelerated by the spring force during a time starting when the disk cartridge is inserted into the disk holder and ending when the disk cartridge is loaded, and, then, the slider slides at an approximately fixed speed. Therefore, at a time when the slider reaches a sliding completion position, the magnetic head comes into contact with the magnetic disk so strongly that a magnetic film on the surface of the magnetic disk may be damaged.
In order to eliminate such a problem, in the device in the related art, a damper for decelerating the slider is provided. An oil damper is used as such a damper. The oil damper includes a gear engaging with a rack provided on the slider, a rotating body which rotates together with the gear, and a container which is filled with grease and contains the rotating body. In this oil damper, when the rotating body provided in the container rotates as a result of the slider sliding, the rotating body is decelerated due to viscosity resistance of the grease provided in the container, and the slider is decelerated.
However, in the above-described disk device in the related art, the viscosity of the grease provided in the container depends on the temperature. That is, when the temperature is low, the viscosity resistance of the grease is so large that it is not possible to positively perform the loading operation of the magnetic disk. Further, when the temperature is high, because the viscosity resistance of the grease is small, the loading operation is performed so strongly that the magnetic film of the magnetic disk may be damaged.
Further, in the magnetic disk device, achievement of high-density recording has been attempted as a result of the rotation speed of the magnetic disk being increased, and, thus, the storage capacity of the magnetic disk has been increased. In such a type of a magnetic disk device, buoyant force, caused by an air flow generated due to high-speed rotation of the magnetic disk, is applied to the magnetic head. Thereby, magnetic recording/reproducing can be performed in a condition in which the magnetic head slightly floats above the magnetic disk so that the surface of the magnetic disk is not damaged.
However, in a condition in which the magnetic disk rotates at low speed, no sufficient buoyant force is applied to the magnetic head. Therefore, when the magnetic head is caused to approach the magnetic disk in the condition in which the magnetic disk rotates at low speed, the magnetic head comes into contact with the magnetic disk, and, as a result, a possibility that the magnetic film formed on the surface of the magnetic disk is damaged is high.
Further, in an ejecting condition in which the magnetic disk is ejected from the magnetic disk device or in a waiting condition in which the magnetic head is positioned away from the magnetic disk, the head carriage which supports the magnetic head is locked and the magnetic head is prevented from coming into contact with the magnetic disk so that the magnetic disk is prevented from being damaged.